Paleoceanographic significance of sediment color on western North Atlantic drifts: I. Origin of color
Paleoceanographic significance of sediment color on western North Atlantic drifts: I. Origin of color
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DOI：
10.1016/s0025-3227(02)00321-3
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发表时间：
2002-09-15
期刊：
影响因子：
2.9
通讯作者：
Aller, RC
中科院分区：
文献类型：
--
作者：
Giosan, L;Flood, RD;Aller, RC
在 ODP 第 172 阶段收集的反射光谱与固相铁化学、碳酸盐含量和有机碳含量测量相结合，以评估负责设定沉积物颜色的试剂。因素分析已被证明是一种有价值且快速的技术，可以检测影响沉积物颜色的局部和区域主要因素。在北大西洋西部漂流区，沉积物颜色是原生矿物学和成岩作用变化的结果。沉积物的亮度由碳酸盐含量控制，而色调主要是由于赤铁矿的存在以及粘土矿物中 Fe2+/Fe3+ 的变化。赤铁矿很可能源自加拿大滨海地区的二叠纪-石炭纪红层，由于还原成岩作用和其他沉积成分的稀释作用的差异，在不同地点保存有差异。不同强度的成岩作用是由有机碳含量、沉降速率和厌氧甲烷氧化产生的硫化氢的变化造成的。一硫化铁广泛存在于所有高沉降地点，特别是在冰川时期，这表明冰川中的高陆源通量和/或活性铁通量增加。 (C) 2002 Elsevier Science B.V. 保留所有权利。
Reflectance spectra collected during ODP Leg 172 were used in concert with solid phase iron chemistry, carbonate content, and organic carbon content measurements to evaluate the agents responsible for setting the color in sediments. Factor analysis has proved a valuable and rapid technique to detect the local and regional primary factors that influence sediment color. On the western North Atlantic drifts, sediment color is the result of primary mineralogy as well as diagenetic changes. Sediment lightness is controlled by the carbonate content while the hue is primarily due to the presence of hematite and Fe2+/Fe3+ changes in clay minerals. Hematite, most likely derived from the Permo-Carboniferous red beds of the Canadian Maritimes, is differentially preserved at various sites due to differences in reductive diagenesis and dilution by other sedimentary components. Various intensities for diagenesis result from changes in organic carbon content, sedimentation rates, and H2S production via anaerobic methane oxidation. Iron monosulfides occur extensively at all high sedimentation sites especially in glacial periods suggesting increased high terrigenous flux and/or increased reactive iron flux in glacials. (C) 2002 Elsevier Science B.V. All rights reserved.